Because normal people are more used to calculating degrees — OpenGL is meant to be used simple. Note that all the functions that operate on degrees are “high level” functions. For OpenGL itself, it’s no difference whether it receives radians or degrees — they are internally converted to transformation matrices anyway, so there’s no computational … Read more
The up vector is basically a vector defining your world’s “upwards” direction. In almost all normal cases, this will be the vector (0, 1, 0) i.e. towards positive Y. eye is the position of the camera’s viewpoint, and center is where you are looking at (a position). If you want to use a direction vector … Read more
The point is that your GPU renders triangles, not quads. And it is pretty much trivial to construct a rectangle from two triangles, so the API doesn’t really need to be burdened with the ability to render quads natively. OpenGL is going through a major trimming process, cutting a lot of functionality that made sense … Read more
Windows On Windows you need to include the gl.h header for OpenGL 1.1 support and link against OpenGL32.lib. Both are a part of the Windows SDK. In addition, you might want the following headers which you can get from http://www.opengl.org/registry . <GL/glext.h> – OpenGL 1.2 and above compatibility profile and extension interfaces.. <GL/glcorearb.h> – OpenGL … Read more
Looks like OpenGL is trying to report some error on Win2003, however you’ve not configured your system where to output logging info. You can add the following to the beginning of your program and you’ll see details of the error in stderr. import logging logging.basicConfig() Checkout documentation on logging module to get more config info, … Read more
Yes this is possible. You declare uniform arrays similar to how you’d do it in C, e.g. uniform float v[10]; Then you can set their values using glUniform{1,2,3,4}{f,i}v GLfloat v[10] = {…}; glUniform1fv(glGetUniformLocation(program, “v”), 10, v);
VAOs act similarly to VBOs and textures with regard to how they are bound. Having a single VAO bound for the entire length of your program will yield no performance benefits because you might as well just be rendering without VAOs at all. In fact it may be slower depending on how the implementation intercepts … Read more
One way you can do it is to start with a platonic solid with triangular sides – an octahedron, for example. Then, take each triangle and recursively break it up into smaller triangles, like so: Once you have a sufficient amount of points, you normalize their vectors so that they are all a constant distance … Read more
From a low-level perspective, you can think of an array as having two parts to it: Information about the size, shape, and type of the array (e.g., 32-bit floating point numbers, containing rows of vectors with four elements each). The array data, which is little more than a big blob of bytes. Even though the … Read more
OpenCL is created specifically for computing. When you do scientific computing using OpenGL you always have to think about how to map your computing problem to the graphics context (i.e. talk in terms of textures and geometric primitives like triangles etc.) in order to get your computation going. In OpenCL you just formulate you computation … Read more